This invention relates generally to mail preparation machinery, and more particularly to the collation of insert sheets for stuffing into envelopes.
Mail preparing machines through which printed material is assembled, collated and inserted into envelopes are generally referred to as inserters. Such machines usually are provided with a plurality of insert sheet storing hoppers positioned along the path of a common conveyor onto which the insert sheets are transferred from the supply hoppers. The conveyor is intermittently driven in operative relation to the transfer of insert sheets thereto from the supply hoppers in order to assemble a collated set of insert sheets delivered by the conveyor to a stuffing station at which the collated sets of inserts are inserted into mailing envelopes. Inserter machines of such type are already well known and in use, such as those disclosed in U.S. Pat. Nos. 3,260,517 and 3,965,644. The aforementioned type of inserter machine has a fixed number of supply hoppers within which the inserts are stored at supply stations along the conveyor path to thereby ordinarily limit the number of insert sheets to be stuffed into the envelopes. Accordingly, if the number of inserts stuffed into the envelopes is to be increased, either a larger inserter machine with the requisite number of insert supply hoppers must be utilized or the existing inserter machine must be enlarged by roll-up and attachment thereto of a multi-station assembly of additional insert supply hoppers. In either event, the number of inserts stuffed into each envelope is determined by the number of insert supply hoppers available.
The broad concept of increasing the number of insert sheets to be collated by an inserter machine for stuffing into envelopes, without a corresponding increase in the number of supply hoppers from which the insert sheets are withdrawn, has already been proposed, for example, in U.S. Pat. No. 4,720,960 to Green. The objective of providing a number of sheets in each collated set greater than the number of available supply stacks is achieved according to the Green patent by means of a rather complex method involving the collation of insert sheets into preliminary sets, storing such preliminary collated sets and sequentially transferring the preliminary collated sets on trays to the transport conveyor on which final assembly of collated sheets is performed and delivered to the envelope stuffing station.
It is therefore an important object of the present invention to achieve the overall objective of increasing the insert sheet capacity of an inserter machine, as referred to by way of example in the aforementioned Green patent, in a simpler and more economical and reliable fashion.